Process for the preparation of cotton fibers



Patented June 12, 1928.

UNITED STATES PATENT OFFICE.

PAUL KARRER, OF ZURICH, SWITZERLAND, ASSIGNOR TO THE FIRM CHEMICAL WORKS 1 FORMERLY SANDOZ, F BASEL, SWITZERLAND.

PROCESS FOR THE PREPARATION OF COTTON FIBERS.

No Drawing. Original application filed March 6. 1926, Serial No. 92,953, and in Germany March 11, 1925.

Divided and this application filed July 14. 1927. Serial No. 205,847.

This application is divisional of application Ser. No. 92,953 filed March 6, 1926.

It has been found, that cotton fibers which are more or less esteritied with toluene sul- 5 phonic, benzene sulphonic and naphthalene sulphonic groups, or with aryland alkylsulphonic groups of any kind, can be altered by treating theinwith hetcrocyclic nitrogen compounds, for instance with pyridine, its homologues, quinoline, piperidine, so that the fibers are capable of being directly dyed with acid dyestufls of any kind.

The process can be performed by treating the above mentioned esterified cotton fibers with these substances, pure or dissolved in suitable solvents, which are not injurious to the fibers, for example water, alcohol, etc., or by treating the said fibers in the cold with the above mentioned agents. Certain agents, such as for example pyridine, can also be employed in form of vapor. v

The following example illustrates the inventionflwithout however limiting its scope, 1

the parts being by weight. I

Example.

10 parts of cotton, partially esterified with, toluene sulphonic groups are heated with 120 parts of pyridine for 4 hours at about 100 C. The fibers are afterwards washed, 30 hydroext-racted and dried. They show a considerable ailinity for acid dyestuffs.

\Vhat I claim is:

1. A processfor the preparation of cotton fibers in view of their direct dyeing with acid dyestuffs, consisting in treating cotton fibers which are partially esterified with an organic sulphonic group, with a heterocyclic nitrogen compound.

2. A. process for the preparation of cotton 40 fibers in view of their direct dyeing with acid dyestuffs, consisting in treating cotton fibers which are partially esterified with an organic sulphonic group, with pyridine.

In witness whereof I have hereunto signed my name this 29th day of June 1927.

PAUL KARRER. 

